unusual single ended triode amps

i'm afraid it can't sell more, they are ALL sold.

 

Hi Antonio..

Unfortunately, they are that good..

Low sales seems to involve the owner who has a Laissez Faire attitude to making them.

When you want a new Berning, you typically have to wait about 3 months for one (I understand)

 

You know what I mean, if the topology was that good, it would be used by others too...

 

Obviously.

This bit is much more interesting -

"perfectly"? Them's fighting words. The Berning can be seen as a mosfet switching amp, the transformers acting as inductor coils to filter out the switching frequency. From that POV, the valves act as drivers for the output stage.

I'm not saying anything about the sound, I haven't heard it.

 

An odd way of judging quality. By this logic would you say that Ford cars are better than say Bentleys because they sell more?

Depends on how cost effective it is for others.

 

It doesnt look that sofisticated to make, on the contrary, light and few pieces, ideal for mass production...

 

That's almost funny.

 

So we are agreed that they are not audio output transformers as these are, and always have been, designed to handle the fully frequency range of the audio band?

Power is transferred from the valve to the speakers as the plate current in the valve varies in response to the audio signal on it's grid. As the anode current increases, the current drawn from the converter bridge power supply increases in proportion to the converter transformer ratio. Since the speaker is connected in series to the primary winding , it's current increases by the same amount.

The switching transistors in the impedance converter bridge are not variables in the signal path. The current through the loudspeaker load follows the transfer characteristics of the valve. With a Mosfet switching amplifier, the signal is converted to PWM . With the Berning this is not the case . So again from my point of view, to use the term switching amp is misleading - switching amps are Class D. This is not class D

You have heard it. But like most people, you won't have appreciated to contribution it was making to the overall sound that you were hearing. I think Chris and Neil have been party to hearing one swapped in and out of systems. Finally, the late great Terry Cain had this to say, which trys to explain some of the confusion in layman's terms.

Antonio. Two issues. One is the technology is patented. Two is these things are vey complex and time consuming to build. If someone had the money to licence the technology and build shiny ZOTL's in China, I have no doubt they would take the market by storm. But I would imagine that the thought of the Chinese building his amps would make David furious - he really doesn't care about the money.

 

Would it be fair to say Class D with valves? Interesting..

 

Oops SM, didn't refresh browser before posting. Not Class D!

 

Every technology is patented, or was at a certain time...

The rest is a nice bedtime story to make you feel special...

 

antonio, amps do differ - although it is nice to think that all properly designer and built amps should sound similar.

 

Antony,

Class D is an interesting subject. We all know that PWM was in fact created in the 60's and Sony experimented with PWM amps in the Seventies (they sounded awful). Class D was then used purely in sonically uncritical areas such as subwoofer amplifers until the late 1990's when people looked at it again.

Nowadays when we think of "digital" switching amps, we think of pioneers like Tripath along with Bel Canto, Tact with the original Millenium (a true digital amplifier created by Toccata in Denmark). The Chronology goes something like this

March 1998 Peter Lyngdorf announces the Tact Millenium at Frankfurt

November 1998 Tripath announced the Class T module. Bel Canto incorporate it in the original Evo 200.2

March 1999 Sharp introduce 1 bit Digital switching amplifier.

The rest in history of course, with so many Tripath based designs released over the past 9 years, many other varients of the circuit from PS Audio, Tact, Hypex and others.

The Berning ZOTL circuit was patented in March 1997, the first ZH270 sold the following month. Nearly two years before the Bel Canto Evo 200.2 and a year before the launch of the Millenium. Truly innovative at the time, and IMHO, still ahead of the competition on many regards today.

Antonio, I feel very comfortable thankyou. Those that have heard it know how good it is. I don't have to rip any of it out, redesign any of the circuits, or remove the feedback loop to enjoy it either. I find that's the rewarding part of buying good amplification. More time for listening to music.

 

Who said that...

 

Money availability and hobbies are not the same for all...

 

What do you mean? You can't afford it or listening to music isn't an important hobby for you? You've spend over €65K on your audio equipment so I can't believe it's the former.

 

I did spend 36K in my Portuguese system, not to mention what was "lost" in upgrades...

In Riga, I spent 12K, not only I dont have the same income, but also I wont stay here forever... Anyone wants to by my "old" system...

Some people also have the DIY hobby, in case you didnt notice, it is not my case, I am doing it because I "need"...

 

A really interesting SET...

http://www.lurcher.org/nick/images/gm70/

 

Indeed. Some nice design features there. Is that a commercial amp or a very well executed home built design?

 

I think it is home built, someone quoted this to me:...